Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Apr 21 2023 06:07:19 ACUS02 KWNS 210607 SWODY2 SPC AC 210605 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0105 AM CDT Fri Apr 21 2023 Valid 221200Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CAROLINAS INTO EASTERN VIRGINIA AND MARYLAND... ....SUMMARY... Scattered severe storms are expected from parts of the Carolinas into the Mid Atlantic Saturday afternoon and evening. Hail, damaging gusts, and perhaps a brief tornado will all be possible. A marginal severe threat could also develop in parts of Florida and in parts of Texas. ....Synopsis... A negative-tilt upper trough will swing northeastward across the OH Valley and across the Appalachians during the day, with strong height falls into the Mid Atlantic by late afternoon or early evening. To the west, moderate west/northwest flow aloft will persist over the southern Plains with an upper ridge over the West. At the surface, low pressure will gradually deepen as it moves across western NY into parts of southwest Ontario, with cold front pushing rapidly east across the Carolinas, VA and PA during the afternoon. Ahead of the front, 50s F dewpoints will be common into PA and NJ, with 60+ dewpoints from southeast VA southward. Aiding moisture advection will be a 40+ kt low-level jet at 850 mb, which will also increase low-level shear. Elsewhere, moisture return will occur from Deep South TX up the Rio Grade Valley, reaching parts of central TX late as an east-west oriented cold front makes southward progress through the period. ....Carolina/Mid Atlantic... Heating and moisture advection will lead to a favorably unstable air mass for severe storms as the upper wave and surface trough push east during the afternoon. MLCAPE will exceed 1000 J/kg over much of the warm sector, and primarily from eastern VA southward. Although instability will be weaker farther north into PA and NJ, this will be in the area experiencing strong cooling aloft with the upper vorticity max. Overall, hodographs will favor cellular activity with storms ahead of the cold front. A broken line or perhaps fully linear storm mode may occur with time as the cold front surges. Hail will be favored during the day, and modest SRH values of 100-150 m2/s2 and lack of a cap may support a few supercells. The severe risk is expected to wane as it approaches the coast due to stabilization. ....Parts of central Texas... Little in the way of large-scale lift will exist over the area for much of the day as instability builds with heating and moisture advection. A plume of steep low-level lapse rates is forecast ahead of the front, and isolated storms will be possible after 00Z in the uncapped air mass and near the cold front. Long hodographs will favor hail in the stronger cells, and locally strong gusts. ...Jewell.. 04/21/2023 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .